Record chart quantity indication



April 13, 1937. c. w. LA-PIERRE RECORD CHART QUANTITY INDICATION Filed Nov. 25, 1953 Inventor:

T. w U E .w

Patented Apr. 13, t 1937 PATENT OFFICE RECORD CHART QUANTITY INDICATION Cramer W. La Pierre, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application November 23, 1933, Serial No. 699,357

2 Claims.

My invention relates to methods and arrangements for indicating the amount of sheet material remaining on a roll of such material, or the amount of such material already used, and has for its principal object the provision of a simple arrangement for producing a visual indication on the sheet itself without using additional equipment. Other and further objects and advantages will become apparent as the description proceeds.

My invention is particularly applicable to arrangements for determining the amount of record chart remaining unused in recording instruments and will be described in connection with the record roll of a recording instrument.

It will be understood, however, that my invention is not limited to such use.

In recording instruments of the strip chart type as ordinarily constructed with enclosing casings, the roll from which the record strip is unwound is obscured from view so that it is not possible to determine how soon it will be necessary to renew the roll of record strip without opening or removing the enclosing casing. It is accordingly an object of my invention to provide a visual indication, observable through the window of the record chart, of theamoimt of chart remaining unused.

In accordance withmy invention in its preferred form, the record strip is marked by means of perforations, notches, ink marks, or in any other suitable manner before the record strip is inserted in the recording instrument. The spacing between the markings is varied progressive-= ly from one end of the strip to the other so that,

from the spacing between the markings, the observer can readily determine to what extent the record roll has been used. For convenience, a

scale may be provided in the recording instrument, calibrated in terms of the amount of record strip remaining.

The record strip may, if desired, be marked by rolling up the strip to form a cylinder, and

, placing markings along a radius of the cylin- 5 drical record roll. Then, as the roll is unwound,

since the radius continuously becomes shorter,

the circumference of the roll, and consequently the spacing between the marks, decreases.

The features of my invention, which I believe 50 to be novel and patentable, will be pointed out in the claims appended hereto. A better understanding of my invention itself, however, may

be obtained by referring to the following descrip tion taken in connection with the accompanying drawing, in which Fig. 1 represents in perspective a recording instrument with a portion of the casing broken away in order to expose the interior mechanism and in which one embodiment of my invention is employed; Fig. 2 represents the record strip employed in the embodi- 5 ment of Fig. 1 and illustrates the manner in which the marking is made on the roll; Figs. 3 and 4 represent modified marking arrangements; and Fig. 5 represents an arrangement in which a scale for measuring depletion of the record strip is printed on the strip.

Referring now more in detail to the drawing in which like reference characters refer to like parts throughout, in the arrangement of Fig. 1, a record chart or strip l l is carried by the spools l2 and iii. The chart M cooperates with a marking pen ill in order to produce a continuous record curve 85, providing a continuous record of the values of a variable quantity in a manner which is well understood in the art and does not form a part of the present invention. In the operation of a recording instrument of this type, the chart is moved along, ordinarily at a uniform rate, by means not shown so that it is gradually unwound from one spool and wound onto the other spool. In the form of chart shown in Fig. l, the direction of motion of the chart is ordinarily downward so that the chart is unrolled from a spool 33, passing around the drum l3, and rolled onto a spool l2 so that the radius of the roll on the spool i2 continuously increases while the radius of the roll on spool i3 continuously decreases.

In order that the quantity of unused record chart remaining on. the spool i3 may be determined without opening the casing it of the recording instrument, I provide markings H on the record chart M. These markings are preferably placed on the record strip while it is on a roll and before it is placed in a recording instrument. The markings ll are not uniformly spaced along the strip but the spacing is pro gsessively varied, becoming greater or less as the chart is used, depending upon the manner in which the chart has been prepared. For example, in the type of marking used in the embodiment of Figs. 1 and 2, a-roll I8 of record strip is provided with the markings II 'by drilling a hole l9 radially into the roll preierablynear one end so as to come along the zero line 20 of the chart, or in any other suitable position so as not to interfere with the marking pen M or to obsome the record IS. The hole 19 is preferably of very small bore and the markings may be made more visible, if desired, by dropping ink into the hole It so as to discolor the edges of the perforations l'l, thereby leaving a colored fringe 2| around each perforation l1.

If the record strip H is prepared as shown in 5 Fig. 2 and then slipped into place on the spool II, it will be obvious thatthe markings I! will be farthest apart when the entire strip is wound on the roll II, and, will gradually become closer and closer together as the chart is rolledtup on spool I 2.

An estimate of the amount of chart remaining on the spool I! can readilybe made by observing the distance between the markings II. In order to obtain a closer indication, a scale 22 may be 16 provided, calibrated in terms of the amount of chart remaining. For example, when the spacing between the markings il corresponds to the spacing between the divisions at the remote ends of the scale 22, the chart II is at the beginning 20 of its use and, when thespacing between the markings l1 corresponds to the spacing between adjacent divisions on the scale 22, the chart II is fully used and has been unwound from spool l3. For the sake of illustration, I have described an arrangement in which the spacing'between the markings decreases as the chart is used, but it will be understood that the chart I l many also be so arranged that the spacing between the markings increases as the chart is used by drilling 3 the hole is into a roll which is rewound onto the spool I}. It will be understood, of course, that if a closer spacing of'all the markings I1 is desired, two or more holes, preferably equidistant angularly, may be drilled into the roll, is instead of merely the single hole l9.

While I have describedthe method of producing the markings II by means of drilling the hole It to produce perforations as being a convenient method of producing the markings, it

40 will be understood that I am not limited to this exact arrangement. For example, in the arrangement of Fig. 3, the markings are produced in the form of notches along the edge of the strip ll, produced by cutting the end of the roll I8 by means of a milling cutter, a saw, or any other suitable tool. A

In the arrangement of Fig. 4, the marks are produced by drawing an ink line'fl radially across the end of the roll It. A suitable ink is employed which penetrates a short distance into the paper of which the roll II is composed so that a series of ink spots I1 is produced along the edgeofthe strip ll.

In the arrangement shown in Fig. 5, the scale 22 is eliminated and a scale is printed directly on the record strip in the form of uniformly spaced lines or marks 2!. In providing the record strip with the variably spaced markings ll', the radial series of markings, e. g., the hole I! in the arso rangement of Fig. 2, is preferably so placed that the bottom of the hole and therefore the inmost of the variably spaced markings l1, coincides in position or is aligned with the inmost of the uniformly spaced scale lines 25, e. g., the scale line 25' at the end of the sheet. Although the spacing of the uniformly spaced scale lines 25 may be made equal to either the minimum spacing or the maximum spacing of the markings II, or a multiple thereof, preferably it is made equal to the minimum spacing. If the latter is the case, as the end of the roll is approached, the spacing between markings I! will become more and more nearly equal to that between the scale lines 25, and the markings 11 will come more and more nearly in alignment with the scale lines 25, thereby indicating very precisely the amount of strip chart remaining on spool II at any time. If desired, the markings of the sets l1 and 15 may also be aligned at the beginning of the roll, or at some other reference point in the record chart instead. It will be understood that, in Fig. 5, the rate of change of spacing between markings I1 is greatly exaggerated in order to represent at the bottom of the chart the appearance where the spacing is nearly a maximum and at the top the appearance where the spacing is approaching a minimum. Obviously, in the actual apparatus, the variation in spacing within the length of chart visible at any one time is scarcely perceptible.

The invention provides a notice to the chart accurate way of determining the amount of un-.

used chart than can otherwise be arrived at by merely observing the diameter of the roll.

In'accordance with the provisions of the pat- .ent statutes, I have described the principle of operation of my invention together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States is:

'1. A method of preparing a strip chart to provide indications of the amount of chart remaining unused which comprises forming the strip chart into a roll and making a radial mark across the end of the roll.

2. The method of producing a series of markings in a longitudinal row on a strip of sheet material and causing the spacing of the markings to vary. progressively, which comprises rolling up the strip to form a cylinder and passing a marking implement along a radius of said cylinder.

CRAMER W. LA PIERRE; 

